Privacy Policy

Comprestack (https://www.comprestack.com) is made by Comprestack, based in Belfast, United Kingdom. We decide how your personal information is used, which makes us the “controller” under the UK GDPR and the Data Protection Act 2018. You can reach us anytime at hello@comprestack.com.

Your images get special care, because they can contain personal moments and private information.

• We use them only to compress or convert them for you.
• Uploaded and processed files are deleted automatically within 1 hour.
• We never sell them, share them, or use them to train AI models.
• Our team doesn't look at your images. The only exceptions are when you ask us to for support, or when we must investigate illegal content.
• By default we remove hidden photo details such as GPS location. You can choose to keep that information when you process an image.

When you create an account

Your name, email address and profile picture, and how you signed up (email and password).

When you use the service

Details needed to run your plan: how many images you process, file sizes, formats, and usage towards your monthly allowance. Your browser may also keep a short list of recent downloads on your own device while those files are still available.

When you use the service without an account

Guests can try the dashboard with a small daily limit (about 3 images per day, up to 5 MB each). To enforce that fairly we use essential cookies and basic technical checks. We do not use this information for advertising.

When you pay

Our payment partner is the merchant of record. They collect your billing name, address, tax details and payment method. Full card numbers never touch our servers. We keep only what we need to sync your plan and show invoices in the dashboard.

When you contact us

If you send a message through our contact form, we store your name, email, topic and message so we can reply.

Automatically

Your IP address, browser, device type and basic security logs. We use these to keep the service working and prevent abuse. When a CAPTCHA is enabled for guests, that provider may process a short challenge to confirm you're human.

• To run the service: process your images, manage your account and count your usage.
• To handle billing, invoices, tax collection (via our payment partner) and refunds.
• To keep things secure: prevent abuse, spam and fraud, enforce fair usage limits, and apply our Terms.
• To help you when you contact support.
• To send important emails about your account, like receipts and usage alerts.
• To send product updates, only if you choose to. You can turn these off anytime.
• To understand, in aggregate, how the service is used, so we can improve it.

We don't sell your personal information, and we don't use it for advertising.

• Contract: to provide the service you signed up for.
• Legitimate interests: to keep the service secure, prevent abuse, enforce fair guest limits and improve it.
• Consent: for product update emails. You can withdraw consent anytime.
• Legal obligation: to keep billing records and respond to lawful requests.

We use a few trusted companies to run Comprestack. They only process data on our instructions and are bound by data protection agreements where required.

We may also share information if the law requires it, to protect people's safety, or as part of a merger or sale of Comprestack. If that happens, we'll let you know.

We keep this minimal. There are no advertising or tracking cookies.

• Essential — sign-in: cookies that keep you logged in.
• Essential — guest limits: cookies that help us apply the daily guest allowance fairly.
• Preferences: your light or dark mode choice and similar settings, saved in your browser.
• Recent downloads: a short list of download links for jobs you ran in this browser, kept on your device until those links expire (1 hour).
• Analytics: privacy-friendly visit counts that do not build an advertising profile.

• Images: deleted within 1 hour.
• Recent downloads in your browser: removed when links expire or you clear site data.
• Guest limit records: kept for the current day only.
• Account and usage: kept while your account is open. When you delete your account, we remove your personal details within 30 days.
• Contact messages: kept as long as needed to handle your request, then deleted or anonymised.
• Billing records: kept for as long as tax law requires, usually up to 7 years (also held by our payment partner as merchant of record).
• Security logs: kept for up to 30 days.

Wherever you live, you can ask us to:

• Give you a copy of your personal information.
• Correct anything that's wrong. Most details can be changed in your account settings.
• Delete your account and personal information. You can do this yourself in Dashboard → Settings.
• Stop or limit certain uses, like product emails.
• Move your information to another service where that right applies.

Email hello@comprestack.com and we'll reply within 30 days. You also have the right to complain to the UK Information Commissioner's Office (ico.org.uk), or, if you're in the EU, to your local data protection authority. California residents: we don't sell or share personal information as defined by the CCPA/CPRA.

All traffic is encrypted with HTTPS. Developer API keys are stored securely. No system is perfect — if a breach ever affects your personal information, we'll tell you promptly where the law requires it.

Our providers may process data outside your country, including in the United States and the European Economic Area. When that happens, we use approved safeguards, such as the UK International Data Transfer Addendum and the European Commission's Standard Contractual Clauses, or rely on the UK-US Data Bridge where it applies.

Comprestack isn't meant for anyone under 16. If you think a child has given us personal information, contact us and we'll delete it.

If we change this policy in an important way, we'll email account holders before the change takes effect where that's practical. The date at the top always shows the latest version.